Description
The mineral lepidolite is a potassium-lithium-aluminum fluorophyllosilicate with the chemical formula KLi2AlSi4O10F(OH). Colorless, white, yellowish, or pinkish, lepidolite consists of aluminum silicate, potassium hydroxide, and aluminum lithiumate hydroxide, and may contain traces of rubidium. It is characterized by good cleavage. The mineral is opaque and sensitive to acid and hot water, thus losing its color. Its average density is 2.84 and its hardness is 2.5 to 3. The crystal system is monoclinic, and the streak is white. Lepidolite is named after the Greek words lepidion and lithos, meaning "shell" and "stone," respectively. The mineral occurs primarily in lithium-rich pegmatites. The type locality is Pala, San Diego, California, USA.
